Ball returning target for table tennis



June 6, 1939. p FROST 2,161,463

BALL RETURNING TARGET FOR TABLE TENNIS Filed July 6, 1937 4 Sheets-Sheet 1 Fig. 3.

fll 1 I I v' Harold P Frost June 6, 1939. H P. FROST 2,161,463

BALL RETURNING TARGET FOR TABLE TENNIS Filed July 6, 1957 4 Sheets-Sheet 2 Harold R Frost June 6, 1939. H P, FR 2,161,463

BALL RETURNING TARGET FOR TABLE TENNIS Filed July 6, 1937. 4 Sheets-Sheet 5 ZLI/ 1111/ ll III/II Ill/I II [-1111] III I]! III/I Fig.9

Harold P Frost June 6, 1939. H. P. FROST 2,161,463

BALL RETURNING TARGET FOR TABLE TENNIS Filed July 6, 1957 4 Sheets-Sheet 4 Patented June 6, 1939 UNITED STATES PATENT ()FFHCE Harold P. Frost,

Worcester, Mass.

Application July 6, 1937, SerialNo. 151,978

17 Claims.

This invention relates to a ball returning target for table tennis, and more particularly to a target which is so constructed that it may be removably mounted on a standard tennis table and one player may drive a tennis ball thereagainst with any of the standard strokes and the ball will be returned to him within bounds for a further drive.

The art of playing table tennis is one which requires a high degree of skill, speed and dexterity; and both the novice and the expert find it desirable to practice the game at times when partners, and particularly those of the same skill, are not available. Hence, it is desirable to have a substitute which mechanically simulates a partner and returns a drive ball to the player for a further stroke; and such a device should be capable of receiving a ball and returning it within bounds, whatever may have been the type of stroke with which it was driven initially. For efficient practice, the player should be able to drive the ball Without spin, or with a top spin or an under spin, as well as use both high speed and light strokes, and yet have the ball returned to him properly for a further play.

The primary object of this invention is to provide such an apparatus which is constructed in accordance with the scientific principles of the game so that it will return the driven ball to the player and keep it within bounds.

A further object is to provide a traget which may be quickly and readily adjusted so that it may be set up on a tennis table for use in returning to the player a ball which has been driven with any one of various strokes desired in connection with this game.

A further object is to provide a target of this type which has rebounding surfaces of the right character, dimensions and angular arrangements for returning a ball driven with a given type of stroke, and particularly to provide an adjustable or reversible apparatus which is capable of presenting difierent types of rebounding sur faces for use with the different strokes. Further objects will be apparent in thefollowing. disclosure.

Referring to the drawings which illustrate various embodiments of this invention:

Fig. 1 is a perspective View, with parts broken away, of a tennis table having two double bounce 7 target boards arranged thereon, the right hand target being suitable for a chop stroke and the left hand target for a top spin stroke;

Fig. 2 is a diagrammatic plan showing the angular arrangement of the left hand target of Fig. 1, together with the approximate path of a top spinning ball driven thereagainst;

Fig. 3 shows diagrammatically the arrangement of the right hand target of Fig. 1 and an approximate path of the ball; 5

Fig. 4 shows a perspective view of a triple bounce target mounted on the tennis table, parts being broken away;

Fig. 5 is a diagrammatic plan of the angular arrangements of the rebounding surfaces of the construction of Fig. 4 and the path of the ball when the target is used for a top spin stroke;

Fig. 6 shows the triple bounce device of Fig. 4 arranged as a double bounce target for receiving a chop stroke; 15

Fig. 7 shows a diagrammatic plan of the double bounce target of Fig. 6 and the approximate path of the ball;

Fig. 8 is a diagrammatic side elevation of a modified triple bounce construction; 20

Fig. 9 is a diagrammatic plan showing the construction of Fig. 8 in a different arrangement of rebounding surfaces;

Fig. 10 is a perspective view of the reversible back board of Fig. 8;

Fig. 11 is a section on the line I l-I I of Fig. 10;

Fig. 12 is a detail partly broken away showing another manner of adjustably connecting the back and roof boards;

Fig. 13 is a perspective View, partly broken away, showing a triple bounce target having two angularly adjustable roof boards;

Figs. 14 and 15 are details showing the manner of mounting the roof boards of Fig. 13; and

Fig. 16 is a diagrammatic vertical elevation of 35 another arrangement of boards in a triple bounce target.

In accordance with this invention, I have provided a ball returning target for a one-man game of table tennis, which comprises in general 40 two or more boards having extensive, substantially plane rebounding surfaces arranged above one another at such angles relative to each other and to the table top that a ball driven thereagainst within bounds will be returned to the player likewise within bounds for another return stroke. These rebounding surfaces may be fixed at correct angles for the above purpose so as to return a ball delivered with a given type of stroke, or the surfaces may be made adjustable relative to each other within scientifically determined limits so that the player may himself experiment with different strokes and rebounding effects. Also, the materials of the rebounding surfaces may be so chosen that the velocity of the ball and its spin and direction of return may be materially controlled; and in some cases it is desirable that these rebounding surfaces be interchangeable or reversible or otherwise arranged so that the player may vary them at will for desired effects. This device may take various constructional forms, and two or more different types of targets may be employed successively by the player in his practice of the game. It is preferred, although not necessary, that one piece of apparatus be made adjustable for use with all of the different strokes, so that the player may experiment at will.

Each of the targets embodying my invention comprises at least two rebounding surfaces of such angular arrangement and dimensions that a ball driven thereagainst will bounce from one surface to the other and then return to the player within bounds. Fig. 1 shows the general arrangement of a tennis table ID with its net II and net support I2 of standard construction. The target mounted on the table comprises in particular two rebounding surfaces I4 and I5 arranged at such an angle to each other that a ball driven against one of the surfaces will bound to the other and be returned to the player.

Referring first to the apparatus set up on the near or left hand side of the table of Fig. 1 and to the diagrammatic view of Fig. 2, the bottom rebounding surface I4 may be arranged at an angle of about 40 relative to a horizontal line, while the two surfaces I4 and I5 are at an angle of approximately 90. These angles may be widely varied, depending upon the nature of the material used for the bounce surfaces. The dotted line aa, Fig. 2, represents approximately the line of sight from the eye of a player of average height to the rear edge of the table III. This line of sight may be indicated on the surface I4 (Fig. 1) by a black line I5 so that the player will know that if a ball strikes the board below that line it is within bounds. If a ball is driven towards the lower surface I4 in the general direction indicated by the dot and dash line b--b, without regard to the influence of gravity upon the ball, then, depending partly upon the nature of the material used for the rebounding surfaces and their angular arrangement, the ball will be deflected from the surface I l at an angle which causes the ball to strike the upper surface I5 and then be returned towards the player; and this ball, if the angles of the rebounding surfaces are correctly arranged, will be returned within bounds on the table for a further stroke. A ball driven with a top spin, as indicated diagrammatically in Fig. 2, will return to the player while spinning in the same direction, which on the return flight becomes an under spin. For use with a top spin drive, as indicated in Figs. 1 and 2, this apparatus is set about half way between the net and the back of the table and may be turned sideways if desired so that the player may practice cross table and side spin strokes. The distance of the apparatus from the net may be widely changed without affecting the return of the ball detrimentally. If the ball were driven above the line I6 then it, of course, would be out of bounds and a bad shot, and so should not be returned to the player. The target may however be so arranged as to cause a wild ball striking the upper surface to be deflected against the lower surface and returned to the player, so that he will not ordinarily have to chase after the ball.

The two rebounding surfaces I4 and I5 are made of suitable materials and preferably supported in an adjustable angular relationship so that the player may himself experiment With different positions of the board. A simple construction for the purpose comprises two supporting frames for the two rebounding surfaces made of wood or other suitable material which are pivotally connected together and mounted on supporting legs. The rebounding surfaces may be formed of paper board, corrugated cardboard, wood ply or other suitable material of sufficient strength and resiliency to receive a driven ball and cause it to bounce as desired. For the first bounding surface I4, I may use cardboard, and for the upper surface I5 a more resilient plywood, if the surfaces are to absorb some of the driven force of the ball. For the particular angular arrangement shown in Figs. 2 and 3 the board I4 may be made of inch tempered pressed wood of about a 6 inch bounce coefiicient, as hereinafter explained, and the board I5 may be made of a corrugated paper board composed of two plane outside layers of paper cemented to an inner corrugated paper and having a bounce coefficient of about 2 inches.

The strip of board employed for each of the surfaces may be nailed or otherwise supported on the parallel wooden side pieces I B and I9. In the form illustrated, the boards are not supported at their lower and upper ends and thus have a greater degree of resiliency or bouncing activity. The adjacent side pieces I8 and I9 are pivotally secured together, as by a pin 20 and the angle between the boards may be fixed as desired by means of the rods or stiff wire braces 22, which have inturned ends removably fitting into any one of the holes 23 and 24 properly located in the side pieces I8 and I9. The legs 25 pivotally mounted on the pieces I9 by the headed bolts and wing nuts 26 may be set and held in desired bracing positions by clamping the nuts tightly in position.

If the player wishes to practice a chop stroke or drive and under spin ball, then the target may be reversed or rearranged as shown at the right hand portion of Fig. 1 and in Fig. 3. In this case, the two rebounding surfaces may be reversed in position so as to employ the special surface used for the member I4 as the first bounding surface just the same as in the previous arrangement. That is, the ball for an under spin -or chop stroke Will be driven to strike the back board I4 (Fig. 3) and thence rebound tothe lower board I5 and be returned over the net II to the player. In this arrangement, the line of sight may be represented by a further line 28, and the ball should be driven below that line if it is to be within bounds. To reverse the boards, it is merely necessary to turn the target over and swing the legs 25 to the new position and clamp them as shown, so that the beveled, short lever ends will rest on the table. The angle which the lower board I5 makes with the horizontal may be readily adjusted, and, if desired, marks may be placed on the side pieces I8 or I9 to indicate the angular positions of the legs and the bottom board.

While the angles may be widely varied, the board I5 may make an angle of about 9 to 20 degrees with the horizontal and the surface I 4 may make an angle of about 65 to 80, and particularly 70, with the surface I5. These angles depend upon the length of the table board and the bounce characteristics of the surfaces. For the angles shown, the surface I4 may be made of pressed wood and the surface I5 of corrugated all paper, The target of Fig. 3 is preferably set near the net for the chop stroke. It may also be noted that the return ball from the chop stroke has a decided downward curve, as is indicated in Fig. 3, due in part to the type of rebounding surface employed and to the spinning movement of the ball and its anglesof incidence on the rebounding surfaces.

The above described construction involves the use of two rebounding surfaces. In Figs. 4 to 7 inclusive, I have shown a construction which comprises three of such surfaces. This arrangement involves a table or floor board 30, a back board 3| and a roof board 32 arranged above one another. Various types of mounting may be employed for the purpose of supporting these boards at their proper angles. As illustrated, the table board 30, which may comprise paper board or wood ply or .other suitable material, is mounted, as by tacking the same in place, on a rectangular wooden frame having side members 34 and end pieces 35 fastened together. Similarly, the back board 3| may be mounted on wooden end pieces 36. If desired, two side pieces 31 may be secured to the end pieces 36 to form a rectangular frame. The roof board 32 may be similarly mounted, but is shown as merely nailed to two wooden side pieces 38.

The back and table boards are made angularly adjustable by pivotally connecting the side pieces 34 and 36 by means of pins 39 passing through the same. A removable or adjustable brace 40 of stiff wire serves the same as brace 22 to hold the back and table boards in their proper angular arrangement. A series of properly located holes 4| permits adjustment. The roof board 32 may be secured in position by a similar arrangement of braces and pivots; but it is illustrated as mounted on a pair of bolts 43 each of which has a head on one end and a wing nut on the other engaging the side members 36 and 38 and thus adjustably clamping them together. A pointer 44 may be secured to the side pieces 38 and indicate by a series of marks on the wooden pieces 36 what is the angle of adjustment. This arrangement is preferably such that the roof board may be swung to the rear of the back board 3| so as to get it out of the way and provide a double bounce target, as shown in Fig. 6. The rear end of the table board 30 may be mounted on a pair of legs 46 pivotally secured to the end piece 35 by pins which permit the legs to be swung laterally into a desired supporting position or to be moved out of the way as indicated in Fig. 6. A second pair of legs 48 pivoted on the side pieces 34 support the front end of the table board.

When a top spin stroke is to be practiced, the target is adapted to be used in the position and arrangement shown in Fig. 4, in which it is fairly close to the net at its forward end. In order to avoid having the balls get between the lower end of the table board and the top of the net, a further board 50 may be provided, if desired. This is pivotally mounted in front of the table board and arranged so that a ball will be delivered across the top of the net after it strikes that surface. This net board 50 may be made of suitable material, such as paper board, and it is mounted on wooden side pieces 52 which are hinged to the sides 34 of the table board by means of the bolts 53 passing through both the legs 48 and the side pieces 52. These are clamped in place by wing nuts on the ends of the bolts. The legs 43 may be of such a height that a ball will be returned over the net, which is about 6 inches pieces 6|. on two side pieces 33 and the top or roof board 34 is mounted on the side pieces 65. board 66 is carried by the two legs or side pieces high. No particular angular arrangement is required for the net board 50, but this may be located suitably for delivering the ball over the top of the net. If desired, the apparatus may be arranged for location at a considerable distance from the net and the legs 48 suitably sized to insure that the ball will not roll down between ,this apparatus and the net.

As shown in Figs. 4 and 5, the average line of sight cc will strike the table board 30 at the line 56 and any ball which strikes in front of or below that line will be deflected against the back board 3| and then to the roof board 32 and returnedto the player. The angular arrangement of these three surfaces depends upon their lengths and materials; but, as shown in Fig. 5, the table board 3|] may make an angle of about 18 with a horizontal line, while the back board 3| is located at an angle of about 115 relative to the table board 30 and the roof board 32 makes an angle of about 100 to the back board 3|. For these particular angles, the effective length of the table board is about 24 inches from front to rear; the back board is 12 inches high and the roof board 12 inches wide. The table board is preferably made of corrugated cardboard, the back board of plywood and the roof board of corrugated paper, for the above angular arrangement. However, these dimensions, angles and materals may be widely varied without defeating the purpose of the apparatus.

If it is desired to practice the chop or under spin stroke, the apparatus may be arranged as shown in Figs. 6 and '7. In this case, the roof board 32 is either removed or swung to the rear 'of the back board 3|, and the short net board 50 .is turned down to form a supporting leg so that this arrangement will be at about the position indicated by the line dd and any ball which strikes the back board below that line will be within bounds. This ball, if delivered with a chop or under spin stroke, will strike the boards as indicated diagrammatically by the trajectory of Fig. 7. Owing, however to the under spin of the ball and the angular arrangement of the table board 3| and the nature of the bouncing surfaces,

the ball will leave the lower surface on a path which is decidedly curved and thus return to the table for a further stroke as indicated.

In Fig. 8, I have shown a construction adapted for use as either a double or a triple bounce target, which particularly involves reversible and interchangeable parts so that one may employ various types of bouncing surfaces for any of the boards. In the illustrated arrangement, the table board 60 is mounted on two parallel side The back board 62 is likewise mounted The net El, and the parts are arranged generally as shown in Fig. 4. In order that the back and roof boards may be interchangeable or reversible so as to pro- -vide many types of surfaces, they may be mounted as shown particularly in Figs. 10 and 11. In this construction, the board 62 may be nailed on one side of each of members 63, while a further board 68 may be nailed on the reverse side. These boards are spaced apart and each provides its own special .typesof bouncing action. For example, the board 62 may be made of plywood of high bouncing characteristics while the board 68 may be made of cardboard of relatively low characteristics.

. The fastening devices which secure the boards in position comprise slotted metal pieces 10 which are suitably screwed to the end pieces 63. Each is so shaped as to provide a slot of the general shape illustrated, which is so proportioned that a pivotal bolt 12 on an adjacent bouncing board maybe received therein and the parts clamped inplace by means of a wing nut 13 on the bolt, shown in Figs. 10 and 11. The wing nuts have been omitted from Fig. 8. A further pair of metal pieces 15 are mounted on the sides 6| of the table board, as shown in Fig. 8, for pivotally supporting the back board 62. An iron brace 16 connected to the back board support 63 and removably engaging one of the holes 11 in the member 8| serves to support the back board. The boards may be reversed or interchanged as is apparent from inspection of the drawings. The back or the roof board may be turned around end for end in order to use either side thereof. The roof board may also be substituted for the back board by providing the necessary bolt construction indicated in Fig. 11 at the upper end thereof.

This combination of boards may be arranged as shown in Fig. 8, wherein the ball is first caused to strike the back board and then bounce to the roof board and be returned over the net to the player. The parts may also be arranged as indicated in Fig. 9 in which the ball first strikes the table board and then the back board, and in this case the roof board is not employed. This arrangement is particularly used for top spin serves and light strokes. If desired, the parts may be arranged as above described wherein the table board may be struck by the ball first, in which case the device is used as a triple bounce target. The angles of these various boards are preferably arranged about as indicated in the drawings, but considerable variation is permissible.

. Numerous modifications may be made in the construction of Fig. 8, such as is shown in Fig. 12. In this case, the side members 80 have extensive slots 8! opening at their upper ends which are adapted to-slidably carry the bolts 12 of another board. The roof board 82 is shown as a single member mounted on one side of the end pieces 83. By means of the sliding connection, the roof board may be raised or lowered by sliding its supporting bolt 12 within the slot. This construction may be employed for connecting any two boards.

Figs. 13, 14 and 15 illustrate a further modification, wherein a board is so mounted that its intersecting line with the table plane is longitudinal thereof or towards the player, so that a ball driven with a side spin diagonally across the table will be caught by this angularly arranged board and be returned within bounds. The construction of Fig. 13 comprises two of such boards arranged-as side wings and which are preferably adjustable about axes extending both crosswise and lengthwise of the table. These wings are preferably arranged to form the roof bouncing surface. Asshown, the roof comprises two separate boards 85 and 86 which are respectively nailed or otherwise secured to axially parallel wooden, pieces 81 and 88. Each of these sticks .81 and 88 .is in turn pivotally supported at, one .end on a cross piece 90 which has its two cylindrical ends 9|.projecting through similarly shaped holes in the end pieces 92 which form the sup port forthe back board 93. A slot 94 extends into thecylindrical hole and a bolt and wing nut 95 passes through the two spaced members formed by theslot. Owing to the resiliency of the wooden member .92, the bolt 95 may be employed to clamp the ends 9| of the piece 90 fixedly in any angular position.

The support 90 is provided with a similar arrangement for pivotally securing the sticks 81 and 88 in place. This may comprise two metal clips 98 which have .two resilient members 97 spaced by a slot terminating in a hole within which- 1 the cylindrical ends .of the members 81 and 88 may be clamped and held in place by means of the wing nuts on bolts 98 passing through the spaced metal members, as will be readily understood .by inspection of the drawings. Hence, the roof boards or wings 85 and 86 may be revolved about the center lines of their supports 81 and 88 and the two boards 85 and 86 may be raised or lowered by turning the mount 98 relative to the side supporting arms 92. Further metal braces, similar to the brace 40, may also be employed to hold the various parts in proper positions. Various combinations of these features may be made with the constructions of the other figures-of the drawings, and the arrangement of the angularly adjustable boards 85 and 86 may be employed for the back or table boards or both, as maybe desired.

In Fig, 16 I have illustrated a further modification which is especially adapted to give the player more time within which to meet the returning ball. In this arrangement the ball strikes the table. board I09 first, then bounces to the roof board I02 and then either to the back board I04 Or to the table board and then returns to the player. It is preferable that the boards be all constructed of materials of high bounce coefficients, since surfaces of lower resiliency will not return the ball with sufiicient velocity. This arrangement may be used for either top spins or chop spins. The average position for the boards which will take care of both of these strokes is illustrated in the drawings, wherein the table board makes an angle of approximately 40 with a horizontal line while the back board has an angle of about 60 with the horizontal. These two boards may be connected by a hinge I86 and arranged so as not to provide a Wide gap therebetween. -It is necessary,- however, that the roof board I02 be spaced from the table board by a considerable distance so as to leave room for balls returning at various angles. In the preferred construction, the roof board may have its forward edge located at about 36 inches from the table and a few inches forward of the table board. It should be long enough to receive any ball which strikes the table board within bounds, but itis not necessary that its rear edge touch the back board and a wide gap may be left therebetween; since aball driven Within bounds will not go through that-gap. The roof board may be adjusted at various angles but it is preferred for average use that it make an angle of with the horizontal.

The constructional features may comprise any desiredmounting for the various boards. For example, any of the boards may be mounted substantiallyas shown in Fig. 4. Or, as shown, the roof board may be conveniently mounted by pivoting its side pieces I88 between the two frame members I H! which rest at their lower ends on the table and are pivotally connected at NZ to the side members I M of the frame. A wire brace H6 may connect the side pieces and the upright pieces. The back board may be held in place by a brace H8 which connects the upright H and the supporting side members I20 of the back board. A series of holes in the upright may be employed for adjusting the angle of this back board. The side pieces I08 of the roof board are pivotally mounted on and clamped in desired angular positions by means of bolts and nuts I22 which pivotally carry the same on the upper ends of the supports I Ill. The paths of two differently driven balls are indicated by the dotted lines. These show that a ball may bounce directly from the table board I00 to the roof board I02 and thence either to the back board I04 or to the table board and then be returned to the player. The various constructional features of the other figures, such as the angularly adjustable roof boards of Fig. 13, may be incorporated in or substituted for the corresponding or other suitable parts of Fig. 16. Numerous modifications will be readily apparent in view of the above disclosure.

As examples of materials suitable for the bounce surfaces and their relative activities, the following materials are given in the order of their activity, the last named having the highest bounce characteristics. The numerals represent the distances in inches to which the bottom of a standard table tennis ball will bounce when dropped from a height of 12 inches onto the specified surface.

Inches Very lightweight corrugated cardboard 1 Lightweight corrugated cardboard 2% Heavy corrugated cardboard 3% ,.,inch plywood-B-ply 4 4 -inch pressed wood 4 /2 ,-inch plywood3-ply 6 /2-inch soft wood pulp board 6 g-inch tempered pressed wood 7 /2-inch plywood--ply 8 %-inch pine board 8 A -inch tempered pressed wood 8 4-inch plywood-5-ply 8 These materials are standard products on the market and may be readily identified by the above description. Corrugated cardboards, for example, are made of corrugated paper cemented between opposed plane paper sides. A ply wood is made of several layers of thin wood veneer cemented together. Pressed wood is made of WOOd fibres pressed together in the desired shape. One may use many other materials, such as Celotex or plastic wood bodies. Rubber of various degrees of vulcanization may be used for the surface, and either hard or soft rubber may be placed as a layer over a wooden or metal backing. Many other materials are obviously suitable.

The nature of the material employed determines both the angle of two adjacent bounce surfaces and in some cases the vertical width of each surface. If the device of Figs. 1 and 2 has the lower table board made of T g inch tempered pressed wood and if the top board is made of the lightweight corrugated cardboard, then the angle between these two surfaces is preferably about 89 and the angle of the lower surface to the tennis table is about 40 where the effective vertical width of the lower board is 13 inches and that of the upper 16 inches, This arrangement gives a decided under spin to the ball and a vertical bounce. If the materials of these two surfaces are reversed, then while the lower board makes the same angle of 40 with the table, it is desirable to open up the angle between the two boards to 92. This gives a less curved trajectory and a horizontal bounce. Also, it is found that if the combined activity of the two surfaces is high, then the upper board should be raised to make the lower board wider as is permitted by the construction of Fig. 12.

It may also be observed that the more resilient the board material, the higher is the velocity of the returned ball. It is ordinarily desirable if the original spin is to be preserved to have a higher bounding coefiicient or resiliency for that board which reverses the direction of the ball and sends it back towards the player. That is, in the two arrangements of Fig. 1 the first bounce surface is preferably made of pressed wood, while the second bounce surface is a paper board. The ball will rebound with greater velocity from the wooden surface than from the paper. One may vary the velocity of the returning ball or the time interval between strokes by changing the surfaces of these boards, and it is desirable for certain uses that the back board be made reversible and provided with a surface of high resiliency on one side and low resiliency on the other.

The dimensions of the boards may also be widely varied. For example, the boards of Fig. 1 may each be about 1 foot high and not much wider crossways of the table if the target is to be used by an expert; but an amateur may prefer larger board surfaces to take care of his wild shots. For the triple bounce board, the main variation which the player may make during practice is that of adjusting the roof board angle. Ordinarily, the angle of the roof board with the back board will vary between 95 and 105". Above 105 a hard driven ball may go off the table, although a more easily driven ball will come back within bounds. It may also be observed that the triple bounce gives a little more time for the return of the ball than does the double bounce board and that the time element may be lengthened and the velocity of the returned ball may be reduced by using surfaces of low resiliency. A single bounce surface will not give the player ample time for his next stroke. A hard driven stroke may be practiced with a target located at a greater distance from the net if desired. With the triple bounce target in proper adjustment the hardest driven ball within bounds will return within bounds.

The direction of the return and the amount of spin of the ball will depend somewhat upon the angle of incidence to the bounding surface. Ordinarily, the ball tends to rotate always in the same direction, so that a ball delivered with a top spin will return as an under spin, as is indicated by the arrows in the drawings. The amount of spin may be accentuated or decreased by varying the angles of the boards. The angle at which the ball leaves a bounce board also depends in part upon the nature of the board material. The harder and more resilient surface tends to give an angle of emergence closer to the angle of incidence than does a surface of poor resiliency.

If a player drives a ball crossways of the table, the triple bounce target may return the ball within bounds because of a peculiarity of the nature of the rebounding surfaces. This is due to the angle of emergence being less than the angle of incidence and the ball being twisted in its course as it strikes one surface after the other, so that it comes back over the net to the player. That the spin affects the angle of emergence is particularly noted where the roof board is arranged at an angle relative to a vertical plane extending lengthwise of the table as shown in Fig. 13. In that case, a ball coming from the corner of the table does not go back to the opposite corner but tends to straighten out and come down nearer to the middle of the table.

The operations of the targets will be readily understood in the light of the above explanation. It will also be apparent that numerous modifications may be made in the invention without departing from the scope of the appended claims. The details of the construction may be varied within the knowledge of a skilled mechanic, and the nature of the materials of the bounce boards and their sizes, locations and relative angles may be widely changed. Also, various other combinations, as well as those illustrated, of the special features of the different targets may be made, provided they fall within the limits of the claims. The above description is therefore to be interpreted as being merely illustrative of the generalprinciples of the invention as well as of the preferred specific structures, and not as limiting the invention to the forms shown in the drawmgs.

What is claimed as new and protectable by Letters Patent is:

1. A target for table tennis comprising boards having extensive substantially plane rebounding surfaces, the planes of which meet in a substantially horizontal line and means for supporting the same on the tennis table top and for securing them in such contiguity and angular arrangement that a ball driven within bounds will strike and bounce between said surfaces and be returned tothe player for a return stroke.

2 In combination with a tennis table and net, a target comprising boards which provide extensive, rebounding surfaces whose planes meet in a line transverse of the table, means for supporting said boards above the table plane and means for adjustably securing them together in such contiguity and variable angular arrangement that a ball driven normally within bounds against one of said surfaces will bounce between said surfaces and be returned to the player within bounds, for a return stroke.

3. A target for table tennis comprising three boards having extensive substantially plane rebounding surfaces arranged one above the other as a lower table board, a back board and a roof board, and means for holding them in such an angular, relationship that a tennis ball driven within bounds against one of the boards will bounce successively against the other two boards and bereturned towards the player.

4. A target of the type covered by claim 3 having pivotal connections between the adjacent boards and means for adjusting the angular relationship of said boards.

5. A triple bounce target comprising a table board,+a back board and a roof board connected together toform a series of angularly arranged extensive plane surfaces, legs supporting the front and the rear of the table board at an angle relative to the table top on. which the target is mounted, means for holding the back board at an adjustable angle relative to the table board and means for securing the roof board to and above the back board at an adjustable angle, so that a ball driven within bounds will bounce between said surfaces and be returned to the player.

6. A target for table tennis comprising a net board, a table board, a back board and a roof board, means for pivotally connecting the boards in the order named, means for mounting the table board at an angle relative to a horizontal plane, means for mounting the roof board above the table board and the back board between the same, and means for supporting the net board, said boards having extensive plane surfaces arranged at such angles to one another that a ball driven against the target within bounds will bounce between the boards and be returned to the player.

7. A target of the type covered by claim 6 in which the table board is mounted on a rear leg and the net board is pivotally connected to the table board and arranged to be used as a supporting leg.

8. A target for table tennis comprising a plurality of boards having extensive plane surfaces angularly arranged above one another, two of the boards having surfaces of different materials and rebounding characteristics, and means for supporting the boards in such contiguity and angular arrangement that a ball driven thereagainst within bounds will bounce therebetween and be returned to the player.

9. A target of the type covered by claim 8 comprising adjustable securing means for removably mounting either of two boards below the otherin correct angular relationship for returning a driven ball.

10. A target of the type covered by claim 1 comprising membersfor two boards which are pivotally and slidably connected together so as to. vary the effective vertical width of one of the boards and their angular arrangement.

,11. A target for table tennis which comprises a plurality of boards having extensive plane surfaces arranged one above another, means for mounting one board at an angle to the table plane with the intersecting line of their planes transverse to the table, and means for mounting another board at such an angle that the line of intersection of its plane with the table plane extends longitudinally of the table, said parts being so arranged that a ball driven within bounds against one board will bounce to the other and be deflected laterally for return to the player.

12. A target of the type covered by claim II comprising a roof having two wing boards having their planes intersecting at an angle whose intersecting line extends longitudinally of the table.

13. A target for table tennis comprising a table board and a back board mounted at an angle to each other, two roof wing boards mounted for revolving about axes extending both transversely and longitudinally of the table and means for holding the boards in such positions that a ball driven within bounds diagonally of the table will be deflected laterally and returned to the player.

14. A target for table tennis comprising a plurality of boards having extensive substantially plane rebounding surfaces including a lower board and a roof board spaced above and at an angle thereto, and means for supporting the boards in such an angular relationship that a tennis ball driven within bounds against the lower board will bounce to the roof board and return to the lower board and thence towards the player.

15. A target for table tennis comprising a plurality of boards including a lower and two upper boards having extensive plane surfaces, means for mounting the lower board at an angle to the table top so that the intersecting line of their planes is transverse to the table, and means for mounting the upper boards above the lower and in such an angular relationship that the line of intersection of their planes extends longitudinally of the table, said boards being secured in such an angular arrangement that a ball driven Within bounds against the lower board will bounce to one of the upper boards and be deflected laterally and returned towards the player for a return stroke.

16. A target for table tennis comprising two boards having extensive substantially plane re: bounding surfaces, means for supporting the two boards above the table plane and at different angles thereto and with the line of intersection of their planes transverse of the table, and means for adjusting the angular relationship of the two boards relative to each other and to the table so that either board may serve as a table board and the other as a back board and a ball driven within bounds against one of the boards will bounce to the other and be returned to the player for a further stroke.

1'7. A target of the type covered by claim 16 wherein the effective surfaces of the two boards are made of different materials and have difierent bounce characteristics.

' HAROLD P. FROST.

CER'I'iFICATE OF CORRECTION. Patent No, 2,161,1;6 June 6, 19 9. HAROLD P. FROSER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 16, for the Word "drive". read driven; page 2, second column, line 1 .5, for "and".read an; page 6, second column, line 56, claim'lO, after the word "comprising"; insert supporting; and that the said'Letter's Patent should' be read with this correction therein that the same may confom to the record of the case in' the PatentOfiice. v

Signed and sealed this 11th day of July, A. D. 1959.

Henry Van Arsd-ale (Seal) Acting Commissioner of Patents. 

